Container cap



' Oct. 1,1946. LAUVE 2,408,465

CONTAINER CAP Filed May i, 1942 2 Sheets-Sheet 1 .L. L. LAUVE ICONTAINER CAP Filed May 1, 1942 2 Sheets-Sheet 2 LguisL.Lauv,e,

Patented Oct. 1, 1946 UNITED STATES PATENT orFicE .QQNTAINER CAP LouisL. Lauve, Baltimore, Md., assignor to Crown Cork & Seal Company, Inc.,Baltimore,

Md., a corporation of New York Appl cation May 1, 1942, Serial No.441,357

I I 4 Claims.

This invention relates to container caps of the type designed forsnap-on and pry-ofi 'coaction with a peripheral locking ring of acontainer, and

is an improvement on the closure of. Such type disclosed in Patent N0.2,109,805, granted March 1, 1938, to Robert J. Stewart.

The said patent discloses, in particular, a skirted metal cap having sixequi-distantly spaced i -pressed lugs in the skirt, the internaldiameter of the skirt being sufficiently greater than the maximumdiameter of the container locking ring or bead so that upon applicationor removal of the cap the skirt portions intermediate the lugs can flextemporarily inwardly, e.., straighten somewhat, whereby the skirtportions at the lugs are enabled to flex outwardly to release the lugswithout ole-formation, thereof. A cap which is re-usable many times withsubstantially original locking efliciency is thus provided. 7

While the eap of the Stewart patent is entirely satisfactory in use sofar as sealing efficiency is concerned, the considerable number of lugs(six) renders the cap rather difficlllt to remove, particularly when thelugs are formed in the curled lower edge of the skirt. One, reason forthis is that when the pry-oil tool is applied atany point under the capedge and leverage is exerted, lugs immediately adjacent the point ofleverage application tend to be drawn under the locking ring of thecontainer and so resist the tiltingoff of the cap, That is to say, whilethe skirt portions at the lugs should flex outwardly to facilitateremoval and avoid lug deformation, the outward component of the forceexerted on the cap by the I pry-on tool results in a stretching effecttoward the tool which resists outward flexing of the skirt portion, thusopposing the outward camming of the skirt portion by the lugs which areadjacent the tool.

It is stated in the patent that as few as three lugs may be used, andwhile this is so in many situations, a three lug cap may fail where highinternal pressures are encountered. Further, as to the six lug cap, itmight be supposed that case of removal would be facilitated by easingthe top angle of the lugs somewhat into the skirt thereabove, ascompared tothe rather abrupt top angle disclosed in the patent. This,however, does not overcome the above described tendency for the lugsadjacent the point of leverage application to pull under the lockingring in resistance to the outward eammihg action enforced by themovement of the lugs upwardly across the locking ring. For anotherthing, if the tops of the lugs are run. upwardly into the skirt at toowide an angle, the

radial component at the lugs, with the cap applied, may be such that thetop of the cap thereabove will be distorted upwardly, thereby impairingthe seal between the cap and the container lip just .above the lugs.

I have discovered that a cap which will afford an effective seal andwillyet have satisfactory removal characteristics, results when itsskirt is provided with a small number of twin lug formations or dents,the lugs preferably starting in a curled edge of the skirt, running at arather wide angle into the skirt above the curled edge, and being shapedfor point contact with the locking ring when applied. The lug-s of eachtwin lug formation are preferably spaced as closely as possible withrespect to each other without subjecting the skirt to destructivebending stresses in manufacture. By the provision of these twinlugformations, each formation providing; a double point contact with thelocking ring, a'cap having three such formations will, of course, havethe same number of gripping points as a cap having six equi-distantlyspaced lugs. However, the angular extent of the free arcs between twoadjacent lug formations is substantially greater than that betweenadjacent lugs ofa six lug cap whose lugs are equidistantlyspaced, andthese longer arcs can more readily flex toward the locking ring in capremoval or application. As compared to a cap having three equi-distantlyspaced single lugs, the lugs of the twin lug formations may be mergedinto the skirt at a wider angle for the facilitation of cap removal.

In the accompanying drawings, I have shown two variants of the inventionby way of example and the description will proceed with reference Y tothese drawings in which:

' Figure 4, but in a different relationship.

Figure 6 is an enlarged outside fragment of the cap of Figure 1 inelevation.

Figure? is an enlarged inside fragment of the cap in Figure l inelevation.

Figure 8 is a view like that of Figure 4 showing a slightly modifiedform of lug.

Figure 9 is a bottom plan view of a cap in accordance with the inventionwith lug formations of modified design.

Figure 10 is an enlarged fragmental section on line iii-40 of Figure 9,including a portion of a container to which the cap is applied.

Figure 11 is an enlarged fragmental section on line lL-H of Figure 9 andadjacent container portion.

Figure 12 is an enlarged fragmental section on line i2i2 of Figure 9 andadjacent container portion.

Figure 13 is an enlarged outside fragment of the cap of Figure 9 inelevation.

Figure 14 is an enlarged inside fragment 0 the cap of Figure 9 inelevation, and

Figure 15 is a section on line i5l5 of Figure 13.

The cap shown in Figures 1 to 7 is formed of the usual resilient sheetmetal and comprises a circular solid top portion 2| and a substantiallycylindrical depending skirt 22 having at its lower edge a continuousoutwardly curled or rolled edge 23. An annular gasket 24, preferably ofmaterial such as semi-vulcanized rubber, is adhered to the under surfaceof the cap top and the latter, as shown, is provided with a circular topindentation 25. Reference numeral 26 designates a container, here shownas being a glass jar, the container having a mouth 21, an angular lip 28adapted to engage the gasket below the circular indentation 25, acontinuous external locking ring or bead 29, and a pry-off ledge 30which is appropriately spaced below the edge 23 when the cap is appliedto the container as in Figures 1, 3 and 4. With normal tolerances, theinternal diameter of the skirt is materially greater than the maximumdiameter of the ring 29, as seen in Figure 3.

The skirt 22 is provided with three equi-distantly spaced twin lugformations, each of the said formations comprising two lugs 3| and 32struck inwardly in the curled edge. As seen in Figure 4, for example,each lug is of generally flat V-section in a bisecting axial plane andhas a lower portion 33 in the curled edge inclined downwardly andoutwardly from the apex 34 and an upper portion 35 inc1ined upwardl andout wardly and merging into the skirt portion above the curled edge atan angle of about 30. The lower and upper portions of the lugs afiord ashoe horn eifect in the cap applying and removing operations,respectively, easing the lugs across the locking ring in eitherdirection. The circle tangent to the apices 34 of the lugs has adiameter appropriately smaller than the maximum diameter of the ring 29.As seen in Figures 4 and 5, the curled edge is somewhat fiattened at thelugs, but this is merely incidental to the forming operation.

It will be noted that the outer extremity of the edge portion 23'between the lugs 3| and 32 is tangential to the outer circle of the edge23 so that the lugs are well defined. Ordinarily, these lugs are placedas closely together as is possible without; subjecting the skirt todestructive bending stresses in manufacture. The lugs are substantiallyarcuate, perhaps approaching a V, in a sectional plane normal to the capaxis so that during application to the container the lugs have linecontact with the ring 29 and point contact when in finally appliedrelation. The inward curves of the lugs in the curled edge clearlyappear in Figure 2, adjacent ends of the curves of the lugs of each setbeing immediately joined by an outwardly curved portion 23.

The inclination at 33 of the lugs and the diameter of the circletangential to the lower extremities of the said portions are such thatwhen the cap is set on the container, as in Figure 5, pressure appliedto the top of the cap will cause any lug formation above the ring to becammed readily radially outwardly as the lugs move downwardly across thering, the uninterrupted or unmutilated arc portions 36 of the edge 23,between the lug formations, straightening somewhat during this operationso as to avoid or minimize the deforming effect on the lugs. With normaltolerances, the spacing between the locking ring 29 and the arc portions36 is such that when the apices 34 are on the maximum circle of the ring29 the center portions of the arcs will not quite touch the ring. As theapices pass below the maximum circle of the ring the inclined portions35 exert a camming action as the lugs and the arc portions 36 resumesubstantially their original relationship, and gasket 24 is drawnforcibly against lip 28 so that the latter is substantially embedded inthe gasket as shown in Figures 3 and 4.

Due to the double gripping points provided by each of the twin lugformations, the cap is held securely on the container, but due to thelocalization of the gripping zones, and also to the relatively easyangle of the upper lug portions 35, the cap can be readily removed by aprying tool and this without danger of damaging the locking ring. Inview of the outward spacing of the cap skirt from the locking ring, theportions 35 of the lug will always be sufficient to take care of minimumtolerances in the locking ring. The apices 34 should be sumciently lowto permit the portionsv 35 to accommodate maximum tolerances of thelocking ring, it, of course, being necessary in all cases that theportions 35 engage below the ring for locking effect.

The angle of the upper portion 35 may be varied somewhat and in Figure 8the corresponding portion 35 has an angle of around 20. The angle shouldnot be so slight and run so far up into the skirt as to give too much ofa radial component, since, as has been mentioned, in such case the capwill tend to lift just above the lugs so that the seal at these pointsis apt to be impaired.

It may be mentioned that Figures 1 and 2 show a cap in a substantiallyexact commercial size, the inside diameter of the skirt being about 2 /4inches with the circumference thus slightly over seven inches. Theengaging points of the lugs of each lug formation are substantiallyone-half inch apart, this spacing enabling the lugs to be formed withoutdanger of damaging the skirt metal. The same spacing of the twin lugscan be maintained in caps of larger diameter. The distance betweenadjacent sets of lugs is always at least twice the distance between thecontact points of the lugs of each set. In the example shown in Figures1 and 2 the distance between the lugs of each set is about /14 of thecircumference.

If it is desired to space the lugs of the twin lug formations moreclosely, the design shown in Figures 9 to 15 may be used. According tothis modification, the twin lugs 31 and 38 are in effect substantiallythe same as before, but the portion 35 of the curled edge between thelugs terminates outwardly substantially within the outer curve of thefull arc portions of the edge. Since there is less extreme bending ofthis portion 39 as compared to the portion 23' of the first embodiment,

the adjacent lugs can be substantially closer together without danger ofinjury to the metal in manufacture. The lugs 25! and 38 are somewhatsharper, i. e., more nearly of V shape, in cross section than the lugsof the first embodiment, but their contours in axial planes aresubstantiall the same.

The central axial section of the intervening edge portions 39 issubstantially as shown in Figure 11. As in the first embodiment, thereis line contact at each lug during application and point engagement withthe locking ring when the cap is fully engaged; The sealing efliciencyis the same as in the first embodiment, the main difference being thatthe lug formations of the second embodiment are less conspicuous andhence preferable in some situations.

While with three sets of twin lugs added security of seal is afforded asover three equi-distantly spaced single lugs, there is still maintainedthe desirable feature of the latter that the pryingoff at one of the lugformations results in the lifting up of more than half of the cap.

It will be understood that the invention is susceptible of othervariations as to'form and arrangement of parts without departure fromthe scope of the following claims.

I claim:

1. A snap-on andpry-oflf cap including a top and a resilientsubstantially cylindrical skirt depending from said top and including acontinuous curled bottom edge, said skirt being provided with three onlyof substantially equi-distan-tly spaced sets of two inwardly projectinglugs of which each lug of each set has an upper portion which inclinesgradually outwardly and upwardly relative to the inner surface of theskirt above said edge and merges into said surface a distance above saidedge and has a lower portion in said edge inclined gradually downwardlyand outwardly relative to said inner surface, said lugs being eachengageable with point contact under a container locking ring ofsubstantially less maximum diameter than the maximum inside skirtdiameter when the cap is applied, said lower and upper portionsaffording a shoehorn effect in the cap applying and removing operationsrespectively, each lug having an inward curve in the plane of said edgeand the adjacent ends of the curves of the lugs of each set being immediately joined by an outwardly curved portion of said edge, and thedistance between adjacent sets of lugs being at least twice the distancebetween the contact points of the lugs of each set.

2. A snap-on and pry-off cap including a top and a resilientsubstantially cylindrical skirt depending from said-top and including acontinuous curled bottom edge, said skirt being provided with three onlyof substantially equi-distantly spaced sets of two inwardly projectinglugs of which each lu of each set has an upper portion which inclinesgraduall outwardly and upwardly relative to the inner surface of theskirt above said edge and merges into said surface a distance above saidedge and has a lower portion maximum diameter than the maximum insideskirt diameter when the cap is applied, said lower and upper portionsaffording a shoehorn effect in, the cap applying and removing operationsrespectively, the distance between the contact points of the lugs ofeach set of lugs being about one-fourteenth or less of the insidecircumference of the skirt.

3. The combination with a container having a portion defining a mouthterminating in a lip, said portion including a rigid'continuous externallocking ring, of a snap-on and pry-ofi cap including a top and aresilient substantially cylindrical ski-rt depending from said top andhaving a continuous curled bottom edge, a gasket in said cap, said skirtbeing provided with three only of substantially equi-distantly spacedsets of two inwardly projecting lugs of which each lug of each set hasan upper portion which inclines gradually outwardl and upwardly relativeto the inner surface of the skirt above said edge and merges into saidsurface a distance above said edge and has a lower portion in said edgeinclined gradually downwardly and outwardly relative to said innersurface, said lugs being engaged under said ring each with point contactand with a wedging effect so that a continuing axial tension is exertedon said skirt whereby to compress said gasket between the cap top andthe container lip, the internal diameter of said skirt beingsubstantially greater than the maximum diameter of said locking ring,said lower and upper portions affording a shoehorn effect in the capapplying and removing operations respectively, each lug having an inwardcurve in the plane of said edge and the adjacent ends of the curves ofthe lugs of each set being immediately joined by an outwardly curvedportion of said edge, and the distance between adjacent sets of lugsbeing at least twice the distance between the contact points of the lugsof each set.

4. The combination with a container having a portion defining a mouthterminating in a lip, said portion including a rigid continuous externallocking ring, of a snap-on and pry-off cap including a top and aresilient substantially cylindrical skirt depending from said top andhaving a continuous curled bottom edge, agasket in said cap, said skirtbeing provided with three only of substantially equi-distantly spacedsets of two inwardly projecting lugs of which each lug of each set hasan upper portion which inclines gradually outwardly and upwardlyrelative to the inner surface of the skirt above said edge and mergesinto said surface a distance above said edge and has a lower portion insaid edge inclined gradually downwardly and outwardly relative to saidinner surface, said lugs being engaged under said ring each with pointcontact and with a wedging efiect so that a continuing axial tension isexerted on said skirt whereby to compress said gasket between the captop and the container lip, the internal diameter of said skirt beingsubstantially greater than the maximum diameter of said lockin said edgeinclined gradually downwardly and outwardly relative to said innersurface, said lugs being each engageable with point contact under acontainer locking ring of substantially less ingring, said lower andupper portions affording a shoehorn effect in the cap applying andremoving operations respectively, the distance between the contactpoints of the lugs of each set of lugs being about one-fourteenth orless of the inside circumference of the skirt.

LOUIS, L; LAUVE.

